US financial watchdogs have barked that companies can use Twitter, Facebook and other social media to make key announcements as long as they tell investors which sites they will use.

Guidance from the Securities and Exchange Commission has had to clarify disclosure rules after the agency opened an inquiry into a post made last July on the personal Facebook page of Netflix's chief executive, Reed Hastings. It was concerned that his announcement that the movie and TV streaming service had hit 1 billion hours viewed in June violated a rule that requires important information to be disclosed to investors at the same time. In this case it did not initiate an enforcement action or allege wrongdoing in that situation but its staff learned that there was uncertainty about how disclosure rules apply to social media channels.

George Canellos, acting director of the SEC's enforcement division, said in a statement that one set of shareholders should not be able to get a jump on other shareholders just because the company is selectively disclosing important information. He said that social media was perfectly suitable methods for communicating with investors, but not if the access is restricted or if investors don't know that's where they need to turn to get the latest news.